570 



Memoirs of the Indian Museum. 



[Vol. V, 



Table I. 





Specific gravity of water. 1 













Distribution. 



Date of 



Species. 







•A~siA^*<~ vl 



r 



At time of 



Annual range at 





capture. 





capture. 



place of capture. 







A ncistrosyllis constricta 



1*000 — 1*010 



rooo — 1*027 



South and south-west 

 shores ; outer channel. 



S. F. 2 



Tylonereis fauveli 



rooo — 1-0265 



rooo — 1-027 



Outer channel. 



S. F. 



Nereis chilkaënsis 



1-002 — i-oii 



rooi — 1-015 



South of lake. 



S. F. 



Nereis reducta 



rooo 



rooo — 1-027 



Outer channel. 



F. 



Perinereis marjorii 



rooo 



rooo — 1-027 



Outer channel. 



F. 



Nephthys polbranchia 



i-ooi — 1-0115 



rooi — 1015 



South of lake. 



S. F. 



Nephthys oligobranchia 



10015 — 1-0115 



rooi — 1*015 



South of lake. 



S. F. 



Diopatra variabilis 



i-ooo — i-oio 



rooo — 1-015 



South and north-west of 

 lake. 



S. F. 



Marphysa gravelyi 



roo8 — 1-0115 



rooi — roi5 



South of lake. 



S. 



Lumbriconereis polydesma . . 



roil 



roo6 — 1-015 



South of lake. 



S. 



Lumbriconereis simplex 



ron 



roo6 — 1-015 



South of lake. 



s. 



Glycinde oligodon 



rooo — ron 



rooo — 1-026 



South of lake : once at in- 

 ner end of outer channel. 



S. F. 



Scoloplos marsupialis 



1-0264 



1000 — 1-027 



Outer channel. 



S. 



Polydora homelli 



rooo 



rooo — 1-027 



Outer channel. 



F. 



Myriochele picla 



roo5 — roic 



rooi — 1-015 



South of lake. 



S. F. 



Heteromastus similis 



rooo — 1-0261 



1 -ooo — 1-0265 



Inner end of channel, 

 near bar. 



S. F. 



Euclymene annandalei 



1-002 — ron 



i-ooi — 1-015 



South of lake. 



S. F. 



Sternaspis costata 



rooo 



1*000 — 1-027 



Outer channel. 



F. 



Fabricia spongicola 



1 006 — ron 



1*001 — 1*015 



South of lake. 



S. F. 



Laonome indica 



1-009 



1*004 — 1*009 



South of lake". 



S. 



1 At i5°C. 2 S = Salt-water season (February— July) ; F = Freshwater season (September— November). 



When the distribution of the species in Table I is studied, two main groups are 

 easily distinguished. In the first are those species confined to the south end of the 

 lake, which have to withstand variations in the salinity ranging from i-ooi-i/oiS, if 

 spread over the whole area. If very localised in range, the variation may be much 

 less The species in this group are : — 



Group I. 



Nereis chilkaënsis. 

 Nephthys polybranchia. 

 Nephthys oligobranchia. 

 Marphysa gravelyi. 

 Lumbriconereis polydesma. 



Lumbriconereis simplex. 

 Myriochele picta. 

 Euclymene annandalei. 

 Fabricia spongicola. 

 Laonome indica. 



In the second group are those species which have only been found in the Outer 



Channel. These are : — 



Tylonereis fauveli. 

 Nereis reducta. 

 Perinereis marjorii. 



Group II. 



Scoloplos marsupialis. 

 Polydora homelli. 

 Sternaspis costata. 



